Marking Technique for Identifying and Resection Flat Colon Polypoid Lesions or Polyps in Difficult Locations

By Klaus Mönkemüller, MD, PhD, FASGE, FJGES and Reid Wasserman, DO

Virginia Tech Carilion School of Medicine, Virginia, USA

One of the most frustrating aspects of dealing with small, flat, diminutive colon polypoid lesions or those lying in awkward location is their “disappearance” during colonoscopy, especially when the colon is not perfectly well prepped or there is increasing colon motility. 

A useful trick is to focus on the lesion, push the scope towards it and suction the mucosa right next it. This creates a red submucosal suction mark, which then becomes pivotal to re-identify or relocate the polyp.

We have also developed the suction, re-shape and resect technique, which not only has the advantage of relocating the polyp, but also improving its resection (Fig. 2).

Here are the key steps for the suction, re-shape and resect technique: suction application, re-shape because of suction and resection.

a) Application of suction: Once the flat lesion is seen (Fig. 2A and 2B), place the scope directly on it and suction it into the working channel (Fig. 2C). This creates a suction mark, but also “reshapes” the polyp into a “sessile” lesion (Fig. 2D).

b) Re-visualization and re-shape: While applying suction insert the snare into the working channel. The advancement of the snare will displace the air of the dead space of the working channel and likely “detach” it. Detachment of the suctioned polyp also occurs when the suction is discontinued.

c) Execution (resection): What began as a flat lesion now morphed into a pseudo-polyp or “sessile” lesion and is marked (Fig 2D). If for some reason we lose scope position, the polyp is already marked and easy to find. If scope position was not lost, we proceed to immediate resection (cold or hot) (Fig. 2E and 2F).

In summary, these suction strategies in colonoscopy not only aid in the effective treatment of lesions but also streamline the process. The time wasted in re-identifying a “lost” flat lesion can be substantial. The transformation of a flat lesion into a pseudo-polyp using suction provides an enhanced visual and practical advantage, enabling a more precise resection. Such techniques are essential tools in the repertoire of gastroenterological practices.